Calculating-machine.



DUD/nnnunu Patented Mar. 7, 1916.

A. D. HARMON.

CALCULATING MACHINE.

APPLICATION FILED SEPT. 27. 1915.

,ly FI l: l?,

THE COLUMBIA PMNOURAPH C0.. WASHINGTON, D. C.

tUNITED STATES PATENT QFFICF.

ALTON D. HARMON, OF CAMBRIDGE SPRINGS, PENNSYLVANIA.

CALCULATING-MAGHINE.

Application led September 27, 1915.

T0 all whom it may concern Be it known that I, ALTON D. HARMON, a citizen of the United States, residing at Cambridge Springs, in the county of Crawford and State of Pennsylvania, have invented certain new and useful Improvements in Calculating-Machines, and I do hereby declare the following to be a full, clear, and

vexact description oi' the invention, such as will enable others skilled in the art to which it appertains to make and use the same;

This invention relates to calculating machines, for adding and subtracting numerals; and it consists in certain improvements to the machine for which a patent was issued to me on April 20, 1915, No. 1,136,797, as hereinafter Jfully described and claimed.

In the drawings, Figure 1 is a. front view of a calculating machine constructed according to the present invention. Fig. 2 is a detail view ot a portion of the back plate. Fig. 3 is a cross-section through the machine, taken on the line -m in Fig. 1. Fig. 4 is a longitudinal section, taken on the line y-g/ in Fig. 1. Fig. 5 is a detail front view of one of the slides. Fig. 6 is a detail front view of one of the carrying signals. Fig. 7 is a detail sectional view oi' a portion of the back plate, taken on the line e-e in Fig. 2, and drawn to an enlarged scale, and showing a modification.

The machine is preferably constructed of ,thin light metal, but other approved material may be used. The back plate B of the machine is provided on its upper side with projecting guide ribs o arranged parallel to each other and preferably struck up from the surface of the metal.

The slides C are interchangeable and they have slots o in their backs which engage With the ribs b. The slides rest on the back plate, and the ribs keep the side edges of the slides from rubbing against each other.

Each slide has 18 stylus holes in it. The lower 9 holes are .distinguished from the upper 9 holes in any convenient way, and in the example shown the lower holes are square and the upper holes are round. All the holes are arranged at equal distances apart, and the lower holes are arranged out of line with the upper holes. The back plate B has ratchet-shaped toothed racks formed in it. The racks e are arranged under the lower holes d, and their teeth point in the opposite direction from those of the racks Specification of Letters Patent.

Patented Mar. 1916.

Serial No. 52,835.

e which are arranged under the holes d. When a stylus is inserted in the holes Z its point engages with the teeth e, and the slide can be slid downwardly but not upwardly. In the same manner the slides can be slid upwardly by stylus inserted in the holes cZ, but cannot be slid downwardly. In a simple form of the machine these racks are dispensed with, and then the holes (Z and CZ can be placed in line with each other.

The holes Z and d are arranged in one side portion of each slide, and its other side portion is provided with a row of index numerals E, from 0 to 9 inclusive. These numerals are arranged adjacent to the stylus holes, and the numeral 2 is arranged opposite the bottom stylus hole of the series (l. The face plate F extends over all the slides, and is secured to the back plate in any convenient way. The face plate is preferably provided with sides having inwardly projecting flanges f, and the back plate is slidable on the flanges lf between the sides The face plate has also a top end plate Il," which limits the upward sliding movement of the back plate, and positions it correctly. The bottom portion of the face plate has an oi'llset portion 7c which extends beyond its sides j', and which is provided with sight holes it through which the index numerals E of the slides may be seen. By making the part oiset from the front plate the index numerals can be read with facility, as the part 76 is adjacent to the faces of the slides and it does not cast shadows on them which would make the numerals hard to read, and it also enable a suicient space for signal mechanism to be provided letween the face plate and the slides. This signal mechanism will be fully described hereinafter. rThe end plate le at the top of the machine positions the back plate. The slides and the back plate are removable at the bottom ot' the machine, and can be slid out of it at any time so as to give i'ree access to the signal mechanism.

The face plate F has a series of parallel slots g, one for each slide, and arranged so as to expose the stylus holes in the slides. Each bar formed by the slots g has a series of numerals J, 1 to 9 inclusive, marked on it, and arranged at the same distances apart as the stylus holes. The sight holes /zare positioned so that when the cipher 0 on each slide is visible, as shown in Fig. 1, the lowest stylus hole of the series Z is opposite the numeral l of the series of numerals J on the face plate.

rThe bottom ends of the slides C are flush with the bottom end of the bacl: plate and the bottom edge of the offset portion k of the face plate when all the slides are set to zero as shown in Fig. l, and the setting of the slides to zero is accomplished by merely pressing` all of them against any convenient stationary object, so that they are all set to rero simultaneously.

Stops m for limiting the motions ofthe stylus are provided at the lower ends of the slots g, and are formed by the shoulder z' between the face plate and its offset portion 7c. Stops a are provided at the upper ends of the slots g, and are formed by the edge ofl a stop bar N which is secured to the underside of the face plate. This stop bar has notches which form teeth n" which project beyond the upper ends of the slides when the slides are moved downwardly to their full extent, and they prevent the upper ends of the slides from springing upwardly and catching againstV the stop bar. rl`he stops n may be flush with the upper ends of the slots g or they may project a little beyond them. The object of using a stop bar instead of using the ends of the slots as stops is to form a more positive stop for the point of the stylus.

When the ends of the slots form the stops the point of the stylus is frequently pushed up too far, as the stylus is usually held in an inclined position and its point will project under the face plate if the stop bar is not used. rlhe stop bar also stiifens the face plate, and prevents it from being crushed or bent when the machine is in use.

Carrying signals are provided similar to those in the patent hereinbefore mentioned. The levers 79 and s of theV carrying signals have their adjacent ends articulated t0- gether, and their middle parts are pivoted on pins 79 and s respectively which project from the bars of the face plate. The upper lever 79 has teeth t and t on opposite sides of its top end, and the lower lever s has a tooth w which projects from the left hand side of its bottom end.

Fig. 6 shows a carrying signal in its normal position, the bars of the face plate being shown in dotted lines. The teeth t and w are signal teeth, and when the stylus strikes the tooth t it turns the levers on their pivots and exposes the signal teeth at the next left hand slot.

In order to prevent the slides from sliding too freely, and also to prevent the signals from moving pivotally too freely, and to guard against accidental displacements of these parts when the device is in use, double-ended leaf springs R are mounted loosely on the pivot pins 79 and s between the slides and the signals. The end portions of these springs are curved or inclined so that they bear on the slides, and their middle parts bear against the signal levers.

The machine'is used for adding'and for subtracting exactly the same as fully described in the hereinbefore mentioned patent. The stylus is inserted in the stylus hole of a suitable slide opposite the numeral on the face plate which is to he added or subtracted, and the slide is slid in an appropriate direction until the stylus strikes the stop in its path. Each time a stylus strikes a tooth t and operates a signal, an additional 1 must be registered by the stylus by means of the next adjacent left hand slide. This moves back the tooth w and resets the signal. Y

The sum ofthe numerals added together by means of the slides is exhibit-ed through the sight holes h at the lower part of the machine. rlChe provision of the offset por tion c on the face plate enables the numerals on the slides to be read with facility as the offset portion comes nearer the face of the slides than the main portion of the face plate. Y

In the modification shown in Fig. 7, a

stop bar is not used, and lugs N are formed on the .face plate which project down- A wardly from the upperV ends of the slots and form stops which prevent the point of the stylus from being pushed under the face plate. These lugs also engage with the end portions of the slides when slid downwardly to their full extent so that the upper end portions of the slides cannot spring upwardly andV catch against the stops, or spring over the tops' of the guide ribs of the back plate.

`What I claim is:

l. In a calculating machine, a face plate provided with slots and having at one end of the slots a stop shoulder for the stylus and an oset portion, said odset portion being arranged parallel to the face plate and provided with sight holes, a back plate, and adding slides movable in the space between the offset portion and the back plate and having their surfaces arranged in close proX- Y imity to the offset portion so that their numerals are clearly visible through its sight holes, a chamber for signal mechanism being formed between the face plate and the slides.V

2. In a calculating machine, a face plate provided with parallel slots, a back plate secured to the face plate and provided with racks having ratchet-shaped teeth, and slides movable in the space between the said plates and having stylus holes arranged over the racks so that the point of the stylus may engage with the rack teeth and prevent the slides from being moved in the wrong direction.

3. In a calculating machine, a face plate provided with parallel slots, a back plate secured to the face plate and provided with two series or racks having ratchet-shaped teeth, the teeth of one series being arranged in the reverse direction from the teeth of the other series, and slides movable in the space between the said plates and having two series of stylus holes arranged over the respective series of racks.

d. In a calculating machine, a face plate provided with parallel slots, a stop bar secured to the underside of the face plate at the upper ends of the slots and Jforming stops for the stylus, a back plate, and slides arranged in the space between the said plates and provided with stylus holes, the faces of the slides being vadjacent to the underside of the stop bar so that the point of the stylus cannot be pushed under it.

5. In a calculating machine, a face plate provided with parallel slots, a stop bar secured to the underside of the face plate at the upper ends of the slots and forming stops for the stylus and having teeth which project between the slots, a back plate secured to the face plate, and slides arranged under the stop bar and in the space between the said plates and provided with stylus holes, said teeth being arranged to overlap the upper ends of the slides when the slides are moved downwardly to their full extent and the faces of the slides being adjacent to the stop bar so that the point of the stylus cannot be pushed under it.

6. In a calculating machine, a face plate provided with parallel slots, slides movable under the face plate and provided with stylus holes, a carrying signal pivoted under the face plate between two adjacent slots and having lateral projections at its opposite end portions, a back plate under the slides, and a flat spring arranged between the carrying signal and the face of one of the slides and operating to press the slide against the back plate and the signal against the front plate so as to prevent the accidental displacement of the slide and signal.

7. In a calculating machine, a face plate provided with slots, adding slides movable longitudinally under the slots, carrying signals pivoted under the face plate between its slots, a back plate under the slides, and flat springs mounted on the pivots of the carrying signals and arranged between the carrying signals and the faces of the slides and operating to press the signals toward the face plate and the slides toward the back plate.

In testimony whereof I have atiiXed my signature.

AL'ION D. HARMON.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

